Combined drawing-square and miter



('M'odel.)

J. MULLER.

COMBINED DRAWING SQUARE AND MITER.

No. 306,418. Patented Oct. 14, 1884.

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JOHN MULLER, OF KANSAS CITY, MISSOURI.

COMBINED DRAWING-=SQUARE AND MITER.

$PECIFICATION forming part of Letters Patent No. 306,418, dated October 14, 1884.

(Model) To aZZ whom it may concern:

Be it known that I, JOHN llTllLLER, a citize of the United States, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in a DrawingSquare and Miter; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled .in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereomwhich form a part of this specification.

Figure 1 represents the instrument closed and as a simple drawing or carpenters square. Fig. 2 represents the same with the movable half of the squaring head-piece A B O I) removed, but shown by means of the dotted lines as a miter. Fig. 8 represents the movable half of the head-piece A B C D with its inner surface presented.

The letters a a a a a a point out six pins or short posts securely fastened into closely-fitting openings in one half of the head-piece. This half of the head-piece is attached firmly as a square to the rule or arm E F G H, the end of the rule being sunk, as shown inFig.

1, into this half of the head-piece and fastened there, so that the whole surface A B O D on Fig. 1 is smooth.

The letter 0 marks a hole through which the bolt S can pass, and this hole is for a short depth, about one-eighth ofan inch,greater in diameter 011 the inner than on the outerside of theheadpiece. The two pins a a are located in the opposite corners of the longer side of this part of the head-piece, while the other four pins are equidistant from the center of the hole 0.

On the presented surface of the movable part of the head-piece, Fig. 3, are shown ten holes suited in size and depth and position to the pins above described on the other part. The two holes marked h 72/ are intended to receive the pins a a, while the other eight are intended to receive the pins a a (t 0. These eight holes divide into equal parts the eircumference of a circle whose radius is equal to a line drawn from the center of one of the posts a to the center of the hole 0, and the center of this circle corresponds in its position on this part of the head-piece with the center of the hole 0 on the other part thereof. Through the center of this circle an iron bolt with a screw end of a length sufficient to reach from one-quarter to three-eighths of an inch through both halves of the head-piece is fastened. Between the two parts of the head-piece, around the screw-bolt and in the enlarged part of the hole 0, is a spiral spring, 8, of three or four coils of brass wire, long and strong enough, when the nut 11 is .loosened, to throw the two parts of the head-piece apart far enough to take the pins out of the holes and allow the movable half to be swung on thev bolt either to the right or the left. This instrument can be made of any hard wood or of metal. The iron bolt and spiral spring alone are necessarily ofmetal.

To operate the instrument, fit the two parts of the head-piece and screw fast. It is then a common artificers square. Now loosen the nut a, and the coil of brass wire withinihrows apart the head-piece. Turn the movable half of the head-piece to right or left till the pins reach the next holes and screw fast. Itisnow a combined square and miter. By stopping the movable half of the head-piece at any de sired angle and screwing fast, allowing the pins to rest on the opposite surface, instead of entering the holes, lines can be thrown in any direction.

Having thus fully described my invention,

\ what I claim as new, and desire to secure by Letters Patent of the United States, is

The combination, with the rule provided with the rigid half headpiece having a hole, 0, with a diameter at its inner end greater than the diameter at its outer end, the short pins to a a a, equidistant from the hole 0, and the pins to a, near the opposite corners of the longer side of this half head-piece, of a movable half headpiece provided with the corner holes, h h, and the holes 72, arranged in acircle around the screw-bolt a, the spiral spring 8, the screw-bolt u, and the thumb-nut a, sub stantially as specified.

In testimony whereof I affix mysignature in presence of two witnesses.

JOHN M ULLER.

\Vitnesscs:

JAMES G. YOUNG, WILLIAM H. Warrs. 

